The present invention is directed to compounds of formulas (I) and (II) and compositions containing said compounds which bind selectively to somatostatin receptor subtypes and the use of said compounds for treating medical disorders which are mediated by somatostatin receptor subtypes. Somatostatin (somatotropin release inhibiting factor, SRIF), a tetradecapeptide hormone, originally isolated from bovine hypothalami (Brazeau, P. et al., Science 179, 77-79, 1973) has been shown to have a wide range of regulatory effects on the release of a variety of hormones such as growth hormone, prolactin, glucagon, insulin, gastrin (Bloom, S. R. and Poldack, J. M., Brit. Med. J. 295, 288-289, 1987). In addition, antiproliferative properties (Reichlin, S., N. Engl. J. Med. 309, 1495-1501, 1983) have been obtained with somatostatin analogs in metastatic prostatic cancer (Parmar, H. et al, Clin. Exp. Metastasis, 10, 3-11, 1992) and in several other neuroendocrine neoplasms in man (Anthony, L. et al, Acta Oncol., 32, 217-223, 1993). Metabolism of somatostatin by aminopeptidases and carboxypeptidases leads to a short duration of action.
The actions of somatostatin are mediated via membrane bound receptors. The heterogeneity of its biological functions has led to studies to identify structure-activity relationships of peptides analogs at the somatostatin receptors which resulted in the discovery of five receptor subtypes (Yamada, et al, Proc. Natl. Acad. Sci. U.S.A, 89, 251-255, 1992; Raynor, K. et al, Mol. Pharmacol., 44, 385-392, 1993). The functional roles of these receptors are under extensive investigation. Binding to the different types of somatostatin subtypes have been associated with the treatment of the following conditions and/or diseases. Activation of types 2 and 5 have been associated with growth hormone suppression and more particularly GH secreting adenomas (Acromegaly) and TSH secreting adenomas. Activation of type 2 but not type 5 has been associated with treating prolactin secreting adenomas. Other indications associated with activation of the somatostatin subtypes are restenosis, inhibition of insulin and/or glucagon and more particularly diabetes mellitus, hyperlipidemia, insulin insensitivity, Syndrome X, angiopathy, proliferative retinopathy, dawn phenomenon and Nephropathy; inhibition of gastric acid secretion and more particularly peptic ulcers, enterocutaneous and pancreaticocutaneous fistula, irritable bowel syndrome, Dumping syndrome, watery diarrhea syndrome, AIDS related diarrhea, chemotherapy-induced diarrhea, acute or chronic pancreatitis and gastrointestinal hormone secreting tumors; treatment of cancer such as hepatoma; inhibition of angiogenesis, treatment of inflammatory disorders such as arthritis; chronic allograft rejection; angioplasty; preventing graft vessel and gastrointestinal bleeding. Somatostatin agonists can also be used for decreasing body weight in a patient.
In drug research, it is a key issue to minimize side effects by developing highly potent and selective drug molecules. Recent work on the development of nonpeptide structures (Hirschmann, R. et al, J. Am. Chem. Soc. 115, 12550-12568, 1993; Papageorgiou, C. and Borer, X., Bioorg. Med. Chem. Lett. 6, 267-272, 1996) have described compounds with low somatostatin receptor affinity.
Further, compounds of Formula I and II are sodium channel blocker and, thus, exhibit useful pharmacological properties, especially utility for the alleviation of neuropathic pain. Neuropathic pain can be described as pain associated with damage or permanent alteration of the peripheral or central nervous system. Clinical manifestations of neuropathic pain include a sensation of burning or electric shock, feelings of bodily distortion, allodynia and hyperpathia.
Sodium channel-blocking agents have been reported to be effective in the treatment of various disease states. They are in particular useful as local anesthetics, and in the treatment of arrhythmia. It has also been reported for many years that sodium channel-blocking agents may be useful in the treatment of pain, including neuropathic pain; see, for example, Tanelian et al., Pain Forum., 4(2), 75-80, (1995). There is evidence that sodium channel-blocking agents selectively suppress ectopic neural firing in injured nerves, and it is via this mechanism that they are believed to be useful for relieving pain. However, studies carried out on well known sodium channel-blocking agents, for example carbamazepine, phenytoin, lidocaine, mexiletine, and the like, indicate that these agents are not very effective for the treatment of neuropathic pain conditions at moderate dose levels, and that even at these moderate dose levels they are associated with a range of undesirable side effects, such as vertigo, nausea, sommolence, tremor, slurred speech, etc. Pre-clinical evidence demonstrates that sodium channel-blocking agents selectively suppress abnormal ectopic neural firing in injured peripheral and central neurons, and it is via this mechanism that they are believed to be useful for relieving pain. Consistent with this hypothesis, it has been shown that sodium channel accumulate in the peripheral nerve at sites of axonal injury (Devor et al., J. Neurosci, 1993, 132, 1976-1992). Alterations in either the level of expression or distribution of sodium channels with an injured nerve, therefore, have a major influence on the pathophysiology of pain associated with this type of trauma. This concept is supported by the relative success of employing sodium channel modulating agents (e.g., anticonvulsants, local anesthesics) for the treatment of neuroplastic pain. However, pain relief has often been obtained concomitantly with numerous adverse events and/or limitations in efficacy which have restricted tolerability of these drugs. It can be seen that a need still exists for an orally active agent that is effective for the treatment of neuropathic pain, but having fewer side effects.
Another aspect of this invention relates to the use of a compound of Formula I or II for treating neuropathic pain conditions in a mammal that is responsive to sodium channel-blocking agents including: peripheral neuropathies, such as trigeminal neuralgia, postherapeutic neuralgia, radiculopathy, and neuropathy secondary to metastatic infiltration, adiposis dolorosa and burn pain; and central pain conditions following stroke, thalamic lesions and multiple sclerosis, by administering a therapeutically effective amount of a compound of Formula I or II to the mammal.
As a result, the compounds of the invention are indicated for the treatment of any pathology, disorder or clinical condition involving glutamate release in their etiology, including psychiatric disorders (such as schizophrenia, depression, anxiety, panic attacks, attention deficit and cognitive disorders, social withdrawal), hormonal conditions (excess GH, e.g. in the treatment of diabetes mellitus, angiopathy and acromegaly, or LH secretion, e.g., prostrate hypertrophy, menopausal syndrome, corticosterone secretion in stress), metabolic inducted brain damage (hypoglycaemia, non-ketotic hyperglycinaemia (glycine encephalopathy), sulphite oxidase deficiency, hepatic encephalopathy associated with liver failure), emesis, spasticity, epilepsy, tinnitus, pain (e.g. cancer pain, arthritis) and drug (ethanol, opiates, including synthetics with opiate-like effects, e.g. pethidine, methadone etc., cocaine, amphetamine, barbiturates and other sedatives, benzodiazephines, abuse and withdrawal.
Moreover, a compound of the present invention is indicated in the treatment of any pathology involving neuronal damage, for example neurodegenerative disorders such as Alzheimer""s, Huntington""s or Parkinson""s diseases, virus (including HIV)-induced neurodegeneration, Amyotrophic lateral sclerosis (ALS), supra-nuclear palsy, olivoponto-cerebellar atrophy (OPCA), and the actions of environmental, exogenous neurotoxins.
In one aspect, the present invention is directed to a compound of formula (I), 
the racemic-diastereomeric mixtures and optical isomers of said compound of formula (I), the pharmaceutically-acceptable salts or prodrugs thereof or a pharmaceutically acceptable salt of said prodrug,
wherein
- - - represents an optional bond;
X is N or Nxe2x80x94R4, where X is N when both optional bonds are present and X is Nxe2x80x94R4 when the optional bonds are not present;
R1 is H, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94(CH2)mxe2x80x94Z1, xe2x80x94(CH2)mxe2x80x94Z1, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94Z1 or (C0-C6)alkyl-C(O)xe2x80x94NHxe2x80x94(CH2)mxe2x80x94Z3;
Z1 is an optionally substituted moiety selected from the group consisting of (C1-C12)alkyl, benzo[b]thiophene, phenyl, naphthyl, benzo[b]furanyl, thiophene, isoxazolyl, indolyl, 
R2 is (C1-C12)alkyl, (C0-C6)alkyl-C(O)xe2x80x94Oxe2x80x94Z5, (C0-C6)alkyl-C(O)xe2x80x94NHxe2x80x94(CH2)mxe2x80x94Z3 or optionally substituted phenyl;
Z5 is H, (C1-C12)alkyl or (CH2)m-aryl;
Z3 is amino, (C1-C12)alkylamino, N,N-di-(C1-C12)alkylamino, xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)m-phenyl, xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)mxe2x80x94(C1-C6)alkyl or an optionally substituted moiety selected from the group consisting of imidazolyl, pyridinyl and morpholinyl, piperidinyl, piperazinyl, pyrazolidinyl, furanyl and thiophene;
R3 is H;
R4 is H, xe2x80x94C(xe2x95x90Y)xe2x80x94N(X1X2), C(xe2x95x90O)X2 or X2;
Y is O or S;
X2 is xe2x80x94(CH2)mxe2x80x94Y1xe2x80x94X3;
X3 is H or an optionally substituted moiety selected from the group consisting of (C1-C12)alkyl, (C3-C8)cycloalkyl, (C1-C12)alkoxy, aryloxy, (C1-C12)alkylamino, N,N-di-(C1-C12)alkylamino, xe2x80x94CHxe2x80x94di-(C1-C12)alkoxy or phenyl;
R5 is (C1-C12)alkyl, xe2x80x94(CH2)mxe2x80x94Y1xe2x80x94(CH2)m-phenyl-(X1)n, (C3-C12)cycloalkyl, xe2x80x94(CH2)mxe2x80x94Sxe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-Sxe2x80x94Sxe2x80x94(C1-C12)alkyl, xe2x80x94(CH2)mxe2x80x94(C1-C12)alkenyl or an optionally substituted moiety selected from the group consisting of phenyl, furanyl, thiophene, pyrrolyl, pyridinyl and 
Y1 is O, S, NH or a bond;
R6 is H or SO2-phenyl;
R7 is H, alkyl optionally substituted with alkoxy or dialkylamino;
wherein an optionally substituted moiety or optionally substituted phenyl is optionally substituted by one or more substituents, each independently selected from the group consisting of Cl, F, Br, I, CF3, NO2, OH, SO2NH2, CN, N3, xe2x80x94OCF3, (C1-C12)alkoxy, xe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94NHxe2x80x94COxe2x80x94(C1-C6)alkyl, xe2x80x94S-phenyl-(X1)n, xe2x80x94Oxe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94Oxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NH2, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94N-di-((C1-C6)alkyl) and xe2x80x94(C0-C12)alkyl-(X1)n;
X1 for each occurrence is independently selected from the group consisting of hydrogen, Cl, F, Br, I, NO2, OH, xe2x80x94CF3, xe2x80x94OCF3, (C1-C12)alkyl, (C1-C12)alkoxy, xe2x80x94Sxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)m-amino, xe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)mxe2x80x94Nxe2x80x94di-((C1-C6)alkyl), xe2x80x94(CH2)m-phenyl and xe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C3-C6)cycloalkyl;
m for each occurrence is independently 0 or an integer from 1 to 6; and
n for each occurrence is independently an integer from 1 to 5.
A preferred compound of formula (I) is where X is NH; R1 is H; R2 is xe2x80x94CH(CH3)2xe2x80x94COxe2x80x94NHxe2x80x94(CH2)mxe2x80x94Z3 where m in the definition of R2 is 1, 2 or 3;
Z3 is imidazolyl, pyridinyl, morpholino, or N,N-di-ethylamino;
R5 is propyl, n-butyl, n-pentyl, xe2x80x94(CH2)xe2x80x94Oxe2x80x94(CH2)-phenyl, 2-nitro-3-OMe-phenyl, p-t-Bu-phenyl, m-OMe-phenyl, o-OMe-phenyl, p-nitro-phenyl, xe2x80x94(CH2)2xe2x80x94Sxe2x80x94Me, cyclohexyl, m-Br-phenyl, p-S-Me-phenyl, p-N,N-dimethylamino-phenyl, m-methyl-phenyl or 
R6 is H; and R7 is H.
Another preferred compound of formula (I) is where X is NH; R1 is H; R2 is phenyl;
R5 is propyl, n-butyl, n-pentyl, n-heptyl, isobutyl, neopentyl, cyclopropyl, cyclohexyl, xe2x80x94(CH2)2xe2x80x94Sxe2x80x94Me, phenyl, xe2x80x94(CH2)xe2x80x94Oxe2x80x94(CH2)-phenyl, 2-nitro-3-OMe-phenyl, p-t-Bu-phenyl, o-OMe-phenyl, m-OMe-phenyl, p-OMe-phenyl, 3,4,5-tri-OMe-phenyl, p-butoxy-phenyl, 3-ethoxy4-methoxy-phenyl, o-nitro-phenyl, p-nitro-phenyl, p-OCF3-phenyl, o-CF3-phenyl, 3-F-4-OMe-phenyl, o-F-phenyl, o-Br-phenyl, m-Br-phenyl, p-Br-phenyl, 2,4-di-Cl-phenyl, 3,4-di-Cl-phenyl, p-(3-(N,N-dimethylamino)propoxy)phenyl, xe2x80x94(CH2)2xe2x80x94Sxe2x80x94Me, cyclohexyl, p-(Me-CO-NH-)-phenyl, p-t-Bu-phenyl, p-OH-phenyl, p-(-S-Me)-phenyl, p(-S-t-Bu)-phenyl, p-N,N-dimethylamino-phenyl, m-methyl-phenyl, 3-OH-4-Ome-phenyl, p-phenyl-phenyl, 
R6 is H; and R7 is H.
Another preferred compound of formula (I) is where X is NH; R1 is H; R2 is p-OMe-phenyl or p-nitro-phenyl;
R5 is n-butyl, n-pentyl, n-hexyl, isobutyl, cyclohexyl, xe2x80x94(CH2)2xe2x80x94Sxe2x80x94Me, phenyl, m-OMe-phenyl, 2-nitro-3-OMe-phenyl, p-nitro-phenyl, p-t-Bu-phenyl, p-thiomethyl-phenyl, m-Br-phenyl, 2-OMe-4-dimethylamino-phenyl, p-(3-(N,N-dimethylamino)propoxy)phenyl, p-dimethylamino-phenyl, 3-nitro4-Cl-phenyl, xe2x80x94(CH2)xe2x80x94Oxe2x80x94(CH2)-phenyl or 
R6 is H; and R7 is H.
In another aspect, the present invention is directed to a compound of formula (II), 
the racemic-diastereomeric mixtures and optical isomers of said compound of formula (II), the pharmaceutically-acceptable salts or prodrugs thereof or a pharmaceutically acceptable salt of said prodrug,
wherein
- - - represents an optional bond;
J1 is Nxe2x80x94R6 or S;
J2 is Nxe2x80x94R1, O or S;
X is N or Nxe2x80x94R4, where X is N when both optional bonds are present and X is Nxe2x80x94R4 when the optional bonds are not present;
R1 is H, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94(CH2)mxe2x80x94Z1, xe2x80x94(CH2)mxe2x80x94Z1, xe2x80x94(CH2)mxe2x80x94Oxe2x80x94Z1 or (C0-C6)alkyl-C(O)xe2x80x94NHxe2x80x94(CH2)mxe2x80x94Z3;
Z1 is an optionally substituted moiety selected from the group consisting of (C1--C12)alkyl, benzo[b]thiophene, phenyl, naphthyl, benzo[b]furanyl, thiophene, isoxazolyl, indolyl, 
R2 is (C1-C12)alkyl, (C0-C6)alkyl-C(O)xe2x80x94Oxe2x80x94Z5, (C0-C6)alkyl-C(O)xe2x80x94NHxe2x80x94(CH2)mxe2x80x94Z3 or optionally substituted phenyl;
Z5 is H, (C1-C12)alkyl or (CH2)m-aryl;
Z3 is amino, (C1-C12)alkylamino, N,N-di-(C1-C12)alkylamino, xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)m-phenyl, xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)mxe2x80x94(C1-C6)alkyl or an optionally substituted moiety selected from the group consisting of phenyl, imidazolyl, pyridinyl and morpholinyl, piperidinyl, piperazinyl, pyrazolidinyl, furanyl and thiophene;
R3 is H, (C1-C6)alkyl or optionally substituted phenyl;
R4 is H, xe2x80x94C(xe2x95x90Y)xe2x80x94N(X1X2), C(xe2x95x90O)X2 or X2;
Y is O or S;
X2 is H or xe2x80x94(CH2)mxe2x80x94Y1xe2x80x94X3;
X3 is H or an optionally substituted moiety selected from the group consisting of (C1-C12)alkyl, (C3-C8)cycloalkyl, (C1-C12)alkoxy, aryloxy, (C1-C12)alkylamino, N,N-di-(C1-C12)alkylamino, xe2x80x94CHxe2x80x94di-(C1-C12)alkoxy or phenyl;
R5 and R8 are each independently selected from the group consisting of H, (C1-C12)alkyl, xe2x80x94(CH2)mxe2x80x94Y1xe2x80x94(CH2)m-phenyl-(X1)n, (C3-C12)cycloalkyl, (C3-C12)cycloalkenyl, xe2x80x94(CH2)mxe2x80x94Sxe2x80x94(C1-C12)alkyl, (C1-C12)alkyl-Sxe2x80x94Sxe2x80x94(C1-C12)alkyl, xe2x80x94(CH2)mxe2x80x94(C1-C12)alkenyl and an optionally substituted moiety selected from the group consisting of phenyl, furanyl, thiophene, pyrrolyl, pyridinyl and 
xe2x80x83provided that R5 and R8 are not both H at the same time;
or R5 and R8 are taken together with the carbon atom to which they are attached to form 
xe2x80x83spiro(C4-C12)cycloalkyl, 
Y1 is O, S, NH or a bond;
A is a bond, xe2x80x94COxe2x80x94, xe2x80x94C(O)Oxe2x80x94, xe2x80x94C(O)NHxe2x80x94, xe2x80x94C(S)NHxe2x80x94, or xe2x80x94SO2xe2x80x94;
B is a bond or xe2x80x94(CH2)qxe2x80x94, where q is an integer from 1 to 6;
J3 is H, (C1-C6)alkyl, optionally substituted phenyl, optionally substituted heteroaryl or N(R9R10), where R9 and R10 are each independently selected from the group consisting of (C1-C6)alkyl, and optionally substituted phenyl, or R9 and R10 are taken together with the nitrogen to which they are attached to form a ring having 5 to 8 members including the nitrogen atom that R9 and R10 are attached to, where one of the ring members may optionally be an oxygen atom or NR11, where R11 is (C1-C6)alkyl, xe2x80x94C(O)xe2x80x94(C1-C6)alkyl, xe2x80x94C(O)xe2x80x94N(V1V2), xe2x80x94C(S)xe2x80x94N(V1V2), or optionally-substituted-phenyl-(C0-C6)alkyl-, where V1 and V2 are each independently H, (C1-C6)alkyl or optionally-substituted-phenyl-(C0-C6)alkyl;
R6 is H or SO2-phenyl;
R7 is H, Cl, F, Br, I, CF3, NO2, OH, SO2NH2, CN, N3, xe2x80x94OCF3, (C1-C12)alkoxy, xe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94NHxe2x80x94COxe2x80x94(C1-C6)alkyl, xe2x80x94Sxe2x80x94(C1-C12)alkyl, xe2x80x94S-phenyl-(X1)n, xe2x80x94Oxe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94Oxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NH2, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94Nxe2x80x94di-((C1-C6)alkyl) and xe2x80x94(C0-C12)alkyl-(X1)n;
wherein an optionally substituted moiety or optionally substituted phenyl is optionally substituted by one or more substituents, each independently selected from the group consisting of Cl, F, Br, I, CF3, NO2, OH, SO2NH2, CN, N3, xe2x80x94OCF3, (C1-C12)alkoxy, xe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94NHxe2x80x94COxe2x80x94(C1-C6)alkyl, xe2x80x94Sxe2x80x94(C1-C12)alkyl, xe2x80x94S-phenyl-(X1)n, xe2x80x94Oxe2x80x94(CH2)m-phenyl-(X1)n, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94Oxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)mxe2x80x94C(O)xe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NH2, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94Oxe2x80x94(CH2)mxe2x80x94Nxe2x80x94di-((C1-C6)alkyl) and xe2x80x94(C0-C12)alkyl-(X1)n;
X1 for each occurrence is independently selected from the group consisting of hydrogen, Cl, F, Br, I, NO2, OH, xe2x80x94CF3, xe2x80x94OCF3, (C1-C12)alkyl, (C1-C12)alkoxy, xe2x80x94Sxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)m-amino, xe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94(CH2)mxe2x80x94Nxe2x80x94di-((C1-C6)alkyl), xe2x80x94(CH2)m-phenyl and xe2x80x94(CH2)mxe2x80x94NHxe2x80x94(C3-C6)cycloalkyl;
m for each occurrence is independently 0 or an integer from 1 to 6; and
n for each occurrence is independently an integer from 1 to 5.
A preferred group of compounds of the compounds of formula (II) are those having the formula (IIa) 
wherein R3 is H or methyl;
R4 is H or methyl;
R5 is H, methyl, ethyl, butyl, pentyl or hexyl;
R8 is ethyl, butyl, pentyl, hexyl, or cyclohexyl;
or R5 and R8 are taken together with the carbon to which they are attached to form spirocyclohexyl, spirocycloheptyl, spiroadamantyl, 
xe2x80x83or 
xe2x80x83where A is a bond or xe2x80x94C(O)Oxe2x80x94; B is a bond, xe2x80x94(CH2)xe2x80x94 or xe2x80x94(CH2)2xe2x80x94;
J3 is H, or phenyl; and
R7 is H, Me, F, Cl, OH, xe2x80x94O-methyl or xe2x80x94Oxe2x80x94CH2-phenyl.
A more preferred group of compounds of the formula (IIa) are those compounds wherein:
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration, or its hydrochloride salt;
R3 is methyl, R4 and R7 are each hydrogen, R5 and R8 are each n-butyl and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration, or its hydrochloride salt;
R3 and R4 are each hydrogen, R7 is 6-Oxe2x80x94CH2-phenyl, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration, or its hydrochloride salt;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3 and R7 are each hydrogen, R4 is methyl, R5 and R8 are each n-butyl and the imidazolyl is in the R-configuration;
R3, R4 and are each hydrogen, R7 is 7-fluoro, R5 and R8 are each n-pentyl and the imidazolyl is the racemic mixture of the S- and R-configurations;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-hexyl and the imidazolyl is in the R-configuration:
R3, R4 and R7 are each hydrogen, R5 is hydrogen and R8 is hexyl in the S-configuration and the imidazolyl is in the R-configuration, or its fumarate salt;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-butyl and the imidazolyl is in the R-configuration, or its fumarate salt;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-butyl and the imidazolyl is in the S-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each ethyl and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-pentyl and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 is methyl and R8 is cyclohexyl and the imidazolyl is in the R-configuration;
R3 and R4 are each hydrogen, R7 is 6-methyl R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 7-fluoro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-methoxy, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-hydroxy, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-fluoro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations, or its hydrochloride salt;
R3 and R4 are each hydrogen, R7 is 8-methyl, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-methyl, R5 and R8 are each n-pentyl and the imidazolyl is a racemic mixture of the S- and R-configurations; or
R3 and R4 are each hydrogen, R7 is 6-chloro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations.
An even more preferred group of compounds of the formula (IIa) are those compounds selected from the group consisting of
R3, R4 and R7 are each hydrogen, R5 is hydrogen and R8 is hexyl in the S-configuration and the imidazolyl is in the R-configuration, or its fumarate salt;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-butyl and the imidazolyl is in the R-configuration, or its fumarate salt;
R3, R4 and R7 are each hydrogen, R5 and R8 are together 
xe2x80x83and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-butyl and the imidazolyl is in the S-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each ethyl and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 and R8 are each n-pentyl and the imidazolyl is in the R-configuration;
R3, R4 and R7 are each hydrogen, R5 is methyl and R8 is cyclohexyl and the imidazolyl is in the R-configuration;
R3 and R4 are each hydrogen, R7 is 6-methyl R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 7-fluoro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-methoxy, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-hydroxy, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-fluoro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations, or its hydrochloride salt;
R3 and R4 are each hydrogen, R7 is 8-methyl, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations;
R3 and R4 are each hydrogen, R7 is 6-methyl, R5 and R8 are each n-pentyl and the imidazolyl is a racemic mixture of the S- and R-configurations; and
R3 and R4 are each hydrogen, R7 is 6-chloro, R5 and R8 are each n-butyl and the imidazolyl is a racemic mixture of the S- and R-configurations.
In another aspect, this invention is directed to a pharmaceutical composition comprising one or more of a compound of formula (I) or formula (II) or a pharmaceutically acceptable salt thereof, as defined hereinabove, and a pharmaceutically acceptable carrier.
In yet another aspect, the present invention is directed to a method of eliciting an agonist effect from one or more of a somatostatin subtype receptor in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove, to said subject.
In still another aspect, the present invention is directed to a method of eliciting an antagonist effect from one or more of a somatostatin subtype receptor in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove, to said subject.
In a further aspect, the present invention is directed to a method of binding one or more somatostatin subtype receptor in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove, to said subject.
In an even further aspect, this invention is directed to a method of treating acromegaly, restenosis, Crohn""s disease, systemic sclerosis, external and internal pancreatic pseudocysts and ascites, VIPoma, nesidoblastosis, hyperinsulinism, gastrinoma, Zollinger-Ellison Syndrome, diarrhea, AIDS related diarrhea, chemotherapy related diarrhea, scleroderma, Irritable Bowel Syndrome, pancreatitis, small bowel obstruction, gastroesophageal reflux, duodenogastric reflux, Cushing""s Syndrome, gonadotropinoma, hyperparathyroidism, Graves"" Disease, diabetic neuropathy, Paget""s disease, polycystic ovary disease, cancer, cancer cachexia, hypotension, postprandial hypotension, panic attacks, GH secreting adenomas and TSH secreting adenomas, in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove to said subject.
Another aspect of this invention provides a method of treating diabetes mellitus, hyperlipidemia, insulin insensitivity, Syndrome X, angiopathy, proliferative retinopathy, dawn phenomenon and Nephropathy; inhibition of gastric acid secretion and more particularly peptic ulcers, enterocutaneous and pancreaticocutaneous fistula, Dumping syndrome, watery diarrhea syndrome, acute or chronic pancreatitis and gastrointestinal hormone secreting tumors, inhibition of angiogenesis, treatment of inflammatory disorders such as arthritis, chronic allograft rejection, angioplasty, preventing graft vessel and gastrointestinal bleeding in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove to said subject.
In still another aspect, this invention provides a method of inhibiting the proliferation of helicobacter pylori in a subject in need thereof, which comprises administering a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof, as described hereinabove, to said subject.
In still another aspect, this invention provides a method of blocking sodium channel in a subject in need thereof, which comprises administering a compound of formula (I) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a method of blocking sodium channel in a subject in need thereof, which comprises administering a compound of formula (II) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a method of alleviating neuropathic pain in a subject in need thereof, which comprises administering a compound of formula (I) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a method of alleviating neuropathic pain in a subject in need thereof, which comprises administering a compound of formula (II) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a pharmaceutical composition for use as a local anesthetic, comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, and optionally a pharmaceutically acceptable diluent.
In still another aspect, this invention provides a pharmaceutical composition for use as a local anesthetic, comprising a compound of formula (II) or a pharmaceutically acceptable salt thereof, and optionally a pharmaceutically acceptable diluent.
In still another aspect, this invention provides a method of treating any pathology, disorder or clinical condition involving glutamate release in their etiology in a subject in need thereof, comprising administering a compound of formula (I) or a pharmaceutically acceptable salt thereof, to said subject. A preferred method of the immediately foregoing method is wherein the pathology, disorder or clinical condition is selected from the group consisting of psychiatric disorders, hormonal conditions, metabolic inducted brain damage, sulphite oxidase deficiency, hepatic encephalopathy associated with liver failure, emesis, spasticity, epilepsy, tinnitus, pain and drug abuse and withdrawal.
In still another aspect, this invention provides a method of treating any pathology, disorder or clinical condition involving glutamate release in their etiology in a subject in need thereof, comprising administering a compound of formula (II) or a pharmaceutically acceptable salt thereof, to said subject. A preferred method of the immediately foregoing method is wherein the pathology, disorder or clinical condition is selected from the group consisting of psychiatric disorders, hormonal conditions, metabolic inducted brain damage, sulphite oxidase deficiency, hepatic encephalopathy associated with liver failure, emesis, spasticity, epilepsy, tinnitus, pain and drug abuse and withdrawal.
In still another aspect, this invention provides a method of treating any pathology involving neuronal damage in a subject in need thereof, comprising administering a compound of formula (I) or a pharmaceutically acceptable salt thereof, to said subject. A preferred method of the immediately foregoing method is wherein the pathology is selected from the group consisting of Alzheimer""s disease, Huntington""s disease, Parkinson""s diseases, virus (including HIV)-induced neurodegeneration, amyotrophic lateral sclerosis (ALS), supra-nuclear palsy, olivoponto-cerebellar atrophy (OPCA), and the actions of environmental, exogenous neurotoxins.
In still another aspect, this invention provides a method of treating any pathology involving neuronal damage in a subject in need thereof, comprising administering a compound of formula (II) or a pharmaceutically acceptable salt thereof, to said subject. A preferred method of the immediately foregoing method is wherein the pathology is selected from the group consisting of Alzheimer""s disease, Huntington""s disease, Parkinson""s diseases, virus (including HIV)-induced neurodegeneration, amyotrophic lateral sclerosis (ALS), supra-nuclear palsy, olivoponto-cerebellar atrophy (OPCA), and the actions of environmental, exogenous neurotoxins.
In still another aspect, this invention provides a method of treating arrhythmia in a subject in need thereof, comprising administering a compound of formula (I) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a method of treating arrhythmia in a subject in need thereof, comprising administering a compound of formula (II) or a pharmaceutically acceptable salt thereof, to said subject.
In still another aspect, this invention provides a method of treating epilepsy in a subject in need thereof, comprising administering a compound according to claim 1 or a pharmaceutically acceptable salt thereof to said subject.
In still another aspect, this invention provides a method of treating epilepsy in a subject in need thereof, comprising administering a compound according to claim 12 or a pharmaceutically acceptable salt thereof, to said subject.
One of ordinary skill will recognize that certain substituents listed in this invention may have reduced chemical stability when combined with one another or with heteroatoms in the compounds. Such compounds with reduced chemical stability are not preferred.
In general, the compounds of Formula (I) and (II) can be made by processes which include processes known in the chemical arts for the production of compounds. Certain processes for the manufacture of Formula (I) and (II) compounds are provided as further features of the invention and are illustrated by the following reaction schemes and examples.
All of the references and patents cited throughout this disclosure are incorporated herein by reference.
In the above structural formulae and throughout the instant application, the following terms have the indicated meanings unless expressly stated otherwise:
The alkyl groups are intended to include those alkyl groups of the designated length in either a straight or branched configuration. Exemplary of such alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tertiary butyl, pentyl, isopentyl, hexyl, isohexyl and the like.
When the definition C0-alkyl occurs in the definition, it means a single covalent bond.
The alkoxy groups specified above are intended to include those alkoxy groups of the designated length in either a straight or branched configuration. Exemplary of such alkoxy groups are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentoxy, isopentoxy, hexoxy, isohexoxy and the like.
The term halogen or halo is intended to include the halogen atoms fluorine, chlorine, bromine and iodine.
The term cycloalkyl is intended to include a mono-cycloalkyl (e.g., cyclopentyl, cyclohexyl, etc.), a bi-cycloalkyl (e.g., bicyclo[2.2.1]hepta-2,5-diene, etc.) or a tri-cycloalkyl group (e.g., adamantyl, etc.) of the indicated carbon number known to those of skill in the art, optionally having double or triple bonds therein.
The term aryl is intended to include aromatic rings known in the art, which can be mono-cyclic, bi-cyclic or tri-cyclic, such as phenyl, naphthyl, indenyl, azulenyl and anthracene.
The term heterocycle includes mono-cyclic, bi-cyclic and tri-cyclic systems having one or more heteroatoms, such as oxygen, nitrogen and/or sulfur. The ring systems may be aromatic, for example pyridine, indole, quinoline, pyrimidine, thiophene (also known as thienyl), furan, benzothiophene, tetrazole, dihydroindole, indazole, N-formylindole, benzimidazole, thiazole, and thiadiazole. The ring systems may be non-aromatic, for example pyrrolidine, piperidine, morpholine and the like.
What is meant by the following description, which appears in the claims:
xe2x80x9cR9 and R10 are taken together with the nitrogen to which they are attached to form a ring having 5 to 8 members including the nitrogen atom that R9 and R10 are attached to, where one of the ring members may optionally be an oxygen atom or NR11, where R11 is (C1-C6)alkyl, xe2x80x94C(O)xe2x80x94(C1-C6)alkyl, xe2x80x94C(O)xe2x80x94NH2, xe2x80x94C(O)xe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94C(O)xe2x80x94N((C1-C6)alkyl)2, xe2x80x94C(S)xe2x80x94NH2, xe2x80x94C(S)xe2x80x94NHxe2x80x94(C1-C6)alkyl, xe2x80x94C(S)xe2x80x94N((C1-C6)alkyl)2, or optionally-substituted-phenyl-(C0-C6)alkyl-xe2x80x9d
is that the following types of moities result: 
where R11 is as defined hereinabove and the arcs represent the carbon members of the ring (however, the symmetry of the arcs is not intended to indicate that they are necessarily of equal number of carbons).
The chemist of ordinary skill will recognize that certain combinations of heteroatom-containing substituents listed in this invention define compounds which will be less stable under physiological conditions. Accordingly, such compounds are less preferred.
When a chemical structure as used herein has an arrow emanating from it, the arrow indicates the point of attachment. For example, the structure 
is a pentyl group. When an arrow is drawn through a cyclic moiety, the arrow indicates that the cyclic moiety can be attached at any of the available bonding points, for example 
means that the phenyl can be bonded ortho, meta or para to the X group. When an arrow is drawn through a bi-cyclic or a tri-cyclic moiety, the arrow indicates that the bi-cyclic or tri-cyclic ring can be attached at any of the available bonding points in any of the rings, for example 
means that the indole is bonded either through the phenyl portion of the ring or the nitrogen containing ring portion.
In the definition for formula (II) when R5 and R8 are taken together with the carbon atom to which they are attached is defined to be, for example 
the * in the ring indicates that it is the carbon atom that R5 and R8 are attached to, thus, forming a spiro compound.
Compounds of the present invention having the following core structure are numbered according to the following scheme: 
xe2x80x9cTreatmentxe2x80x9d means any treatment of a condition in a mammal, particularly a human, and includes:
(i) preventing the disease from occurring in a subject which may be predisposed to the disease, but has not yet been diagnosed as having it;
(ii) inhibiting the condition, i.e., arresting its development; or
(iii) relieving the condition, i.e. relieving the symptom of pain.
The term xe2x80x9csubjectxe2x80x9d means the recipient of a compound of the present invention, preferrably a mammal and most preferrably a human.
xe2x80x9cDisease state which is treatable by administration of a sodium channel blockerxe2x80x9d is intended to cover all disease states which are generally acknowledged in the art to be usefully treated with sodium channel blockers in general, and those disease states which have been found to be usefully treated by the specific sodium channel blocker of our invention, the compounds of formula (I) or (II). Such disease states include, but are not limited to peripheral neuropathies, such as trigerinal neuralgia, postherapeutic neuralgia, diabetic neuropathy, glossopharymgeal neuralgia, lumbar and cervical radiculopathy, reflex sympathetic dystrophy and causalgia, and neuropathy secondary to metastatic infiltration, adiposis dolorosa, and burn pain; and central pain conditions following stroke, thalmic lesions and multiple sclerosis.
xe2x80x9cTherapeutically effective amountxe2x80x9d refers to that amount of a compound of formula (I) or (II) or a pharmaceutically acceptable salt thereof which is sufficient to effect treatment, as defined above, when administered to a mammal in need of such treatment. The therapeutically effective amount will vary depending on the subject and disease state being treated, the severity of the affliction and the manner of administration, and may be determined routinely by one of ordinary skill in the art. The term xe2x80x9ctherapeutically effective amountxe2x80x9d is implicitly incorporated in the amount of compound administered in a method of the present invention or when said compound is a component in a pharmaceutical composition of the present invention.
The compounds of the instant invention have at least one asymmetric center as noted by the asterisk in the structural formula (I) and (II), above. Additional asymmetric centers may be present on the molecule depending upon the nature of the various substituents on the molecule. Each such asymmetric center will produce two optical isomers and it is intended that all such optical isomers, as separated, pure or partially purified optical isomers, racemic mixtures or diastereomeric mixtures thereof, be included within the scope of the instant invention.
The instant compounds can be generally isolated in the form of their pharmaceutically acceptable acid addition salts, such as the salts derived from using inorganic and organic acids. Examples of such acids are hydrochloric, nitric, sulfuric, phosphoric, acetic, propionic, maleic, succinic, D-tartaric, L-tartaric, malonic, methane sulfonic and the like. In addition, certain compounds containing an acidic function such as a carboxy can be isolated in the form of their inorganic salt in which the counter-ion can be selected from sodium, potassium, lithium, calcium, magnesium and the like, as well as from organic bases.
The pharmaceutically acceptable salts are formed by taking about 1 equivalent of a compound of formula (I) or (II) and contacting it with about 1 equivalent of the appropriate corresponding acid of the salt which is desired. Work-up and isolation of the resulting salt is well-known to those of ordinary skill in the art.
As is known in the art, agonists and antagonists of somatostatin are useful for treating a variety of medical conditions and diseases, such as inhibition of H. pylori proliferation, acromegaly, restenosis, Crohn""s disease, systemic sclerosis, external and internal pancreatic pseudocysts and ascites, VIPoma, nesidoblastosis, hyperinsulinism, gastrinoma, Zollinger-Ellison Syndrome, diarrhea, AIDS related diarrhea, chemotherapy related diarrhea, scleroderma, Irritable Bowel Syndrome, pancreatitis, small bowel obstruction, gastroesophageal reflux, duodenogastric reflux and in treating endocrinological diseases and/or conditions, such as Cushing""s Syndrome, gonadotropinoma, hyperparathyroidism, Graves"" Disease, diabetic neuropathy, Paget""s disease, and polycystic ovary disease; in treating various types of cancer such as thyroid cancer, hepatome, leukemia, meningioma and conditions associated with cancer such as cancer cachexia; in the treatment of such conditions as hypotension such as orthostatic hypotension and postprandial hypotension and panic attacks; GH secreting adenomas (Acromegaly) and TSH secreting adenomas. Activation of type 2 but not type 5 subtype receptor has been associated with treating prolactin secreting adenomas. Other indications associated with activation of the somatostatin subtypes are inhibition of insulin and/or glucagon and more particularly diabetes mellitus, hyperlipidemia, insulin insensitivity, Syndrome X, angiopathy, proliferative retinopathy, dawn phenomenon and Nephropathy; inhibition of gastric acid secretion and more particularly peptic ulcers, enterocutaneous and pancreaticocutaneous fistula, Dumping syndrome, watery diarrhea syndrome, acute or chronic pancreatitis and gastrointestinal hormone secreting tumors; inhibition of angiogenesis, treatment of inflammatory disorders such as arthritis; chronic allograft rejection: angioplasty; preventing graft vessel and gastrointestinal bleeding. Somatostatin agonists can also be used for decreasing body weight in a patient. Accordingly, the compounds of the instant invention are useful for the foregoing methods.
Accordingly, the present invention includes within its scope pharmaceutical compositions comprising, as an active ingredient, at least one of the compounds of Formula (I) or (II) in association with a pharmaceutically acceptable carrier.
The compounds of this invention can be administered by oral, parenteral (e.g., intramuscular, intraperitoneal, intravenous or subcutaneous injection, or implant), nasal, vaginal, rectal, sublingual or topical routes of administration and can be formulated with pharmaceutically acceptable carriers to provide dosage forms appropriate for each route of administration.
Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the active compound is admixed with at least one inert pharmaceutically acceptable carrier such as sucrose, lactose, or starch. Such dosage forms can also comprise, as is normal practice, additional substances other than such inert diluents, e.g., lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, the elixirs containing inert diluents commonly used in the art, such as water. Besides such inert diluents, compositions can also include adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavoring and perfuming agents.
Preparations according to this invention for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions. Examples of non-aqueous solvents or vehicles are propylene glycol, polyethylene glycol, vegetable oils, such as olive oil and corn oil, gelatin, and injectable organic esters such as ethyl oleate. Such dosage forms may also contain adjuvants such as preserving, wetting, emulsifying, and dispersing agents. They may be sterilized by, for example, filtration through a bacteria-retaining filter, by incorporating sterilizing agents into the compositions, by irradiating the compositions, or by heating the compositions. They can also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, or some other sterile injectable medium immediately before use.
Compositions for rectal or vaginal administration are preferably suppositories which may contain, in addition to the active substance, excipients such as coca butter or a suppository wax.
Compositions for nasal or sublingual administration are also prepared with standard excipients well known in the art.
Further, a compound of this invention of formula (I) or (II) can be administered in a sustained release composition such as those described in the following patents. U.S. Pat. No. 5,672,659 teaches sustained release compositions comprising a bioactive agent and a polyester. U.S. Pat. No. 5,595,760 teaches sustained release compositions comprising a bioactive agent in a gelable form. U.S. application Ser. No. 08/929,363 filed Sep. 9, 1997, teaches polymeric sustained release compositions comprising a bioactive agent and chitosan. U.S. application Ser. No. 08/740,778 filed Nov. 1, 1996, teaches sustained release compositions comprising a bioactive agent and cyclodextrin. U.S. application Ser. No. 09/015,394 filed Jan. 29, 1998, teaches absorbable sustained release compositions of a bioactive agent. The teachings of the foregoing patents and applications are incorporated herein by reference.
In general, an effective dosage of a compound of the present invention of the formula (I) or (II) in the compositions of this invention may be varied; however, it is necessary that the amount of the active ingredient be such that a suitable dosage form is obtained. The selected dosage depends upon the desired therapeutic effect, on the route of administration, and on the duration of the treatment, all of which are within the realm of knowledge of one of ordinary skill in the art. Generally, dosage levels of between 0.0001 to 100 mg/kg of body weight daily are administered to humans and other animals, e.g., mammals.
A preferred dosage range is 0.01 to 10.0 mg/kg of body weight daily, which can be administered as a single dose or divided into multiple doses.
Compounds of the instant invention can be and were assessed for its ability to bind to a somatostatin subtype receptor according to the following assays. Human somatostatin subtype receptor binding studies:
The affinity of a compound for human somatostatin subtype receptors 1 to 5 (sst1, sst2, sst3, sst4 and sst5, respectively) is determined by measuring the inhibition of [125I -Tyr11]SRIF-14 binding to CHO-K1 transfected cells.
The human sst1 receptor gene was cloned as a genomic fragment. A 1.5 Kb PstI-XmnI segment containg 100 bp of the 5xe2x80x2-untranslated region, 1.17 Kb of the entire coding region, and 230 bp of the 3xe2x80x2-untranslated region was modified by the Bg1II linker addition. The resulting DNA fragment was subcloned into the BamHI site of a pCMV-81 to produce the mammalian expression plasmid (provided by Dr. Graeme Bell, Univ. Chicago). A clonal cell line stably expressing the sst1 receptor was obtained by transfection into CHO-K1 cells (ATCC) using the calcium phosphate co-precipitation method (1). The plasmid pRSV-neo (ATCC) was included as a selectable marker. Clonal cell lines were selected in RPMI 1640 media containing 0.5 mg/ml of G418 (Gibco), ring cloned, and expanded into culture.
The human sst2 somatostatin receptor gene, isolated as a 1.7 Kb BamHI-HindIII genomic DNA fragment and subcloned into the plasmid vector pGEM3Z (Promega), was kindly provided by Dr. G. Bell (Univ. of Chicago). The mammalian cell expression vector is constructed by inserting the 1.7 Kb BamH1-HindII fragment into compatible restriction endonuclease sites in the plasmid pCMV5. A clonal cell line is obtained by transfection into CHO-K1 cells using the calcium phosphate co-precipitation method. The plasmid pRSV-neo is included as a selectable marker.
The human sst3 was isolated at genomic fragment, and the complete coding sequence was contained within a 2.4 Kb BamHI/HindIII fragment. The mammalian expression plasmid, pCMV-h3 was constructed by inserting the a 2.0 Kb NcoI-HindIII fragment into the EcoR1 site of the pCMV vector after modification of the ends and addition of EcoR1 linkers. A clonal cell line stably expressing the sst3 receptor was obtained by transfection into CHO-K1 cells (ATCC) using the calcium phosphate co-precipitation method. The plasmid pRSV-neo (ATCC) was included as a selectable marker. Clonal cell lines were selected in RPMI 1640 media containing 0.5 mg/ml of G418 (Gibco), ring cloned, and expanded into culture.
The human sst4 receptor expression plasmid, pCMV-HX was provided by Dr. Graeme Bell (Univ. Chicago). The vector contains the 1.4 Kb NheIxe2x80x94NheI genomic fragment encoding the human sst4, 456 bp of the 5xe2x80x2-untranslated region and 200 bp of the 3xe2x80x2-untranslated region, clone into the XbaI/EcoR1 sites of PCMV-HX. A clonal cell line stably expressing the sst4 receptor was obtained by transfection into CHO-K1 cells (ATCC) using the calcium phosphate co-precipitation method. The plasmid pRSV-neo (ATCC) was included as a selectable marker. Clonal cell lines were selected in RPMI 1640 media containing 0.5 mg/ml of G418 (Gibco), ring cloned, and expanded into culture.
The human sst5 gene was obtained by PCR using a xcex genomic clone as a template, and kindly provided by Dr. Graeme Bell (Univ. Chicago). The resulting 1.2 Kb PCR fragment contained 21 base pairs of the 5xe2x80x2-untranslated region, the full coding region, and 55 bp of the 3xe2x80x2-untranslated region. The clone was inserted into EcoR1 site of the plasmid pBSSK(+). The insert was recovered as a 1.2 Kb HindIII-XbaI fragment for subcloning into pCVM5 mammalian expression vector. A clonal cell line stably expressing the SST5 receptor was obtained by transfection into CHO-K1 cells (ATCC) using the calcium phosphate co-precipitation method. The plasmid pRSV-neo (ATCC) was included as a selectable marker. Clonal cell lines were selected in RPMI 1640 media containing 0.5 mg/ml of G418 (Gibco), ring cloned, and expanded into culture.
CHO-K1 cells stably expressing one of the human sst receptor are grown in RPMI 1640 containing 10% fetal calf serum and 0.4 mg/ml geneticin. Cells are collected with 0.5 mM EDTA, and centrifuged at 500 g for about 5 min. at about 4xc2x0 C. The pellet is resuspended in 50 mM Tris, pH 7.4 and centrifuged twice at 500 g for about 5 min. at about 4xc2x0 C. The cells are lysed by sonication and centrifuged at 39000 g for about 10 min. at about 4xc2x0 C. The pellet is resuspended in the same buffer and centrifuged at 50000 g for about 10 min. at about 4xc2x0 C. and membranes in resulting pellet are stored at xe2x88x9280xc2x0 C.
Competitive inhibition experiments of [125I-Tyr11]SRIF-14 binding are run in duplicate in polypropylene 96 well plates. Cell membranes (10 xcexcg protein/well) are incubated with [125I-Tyr11]SRIF-14 (0.05 nM) for about 60 min. at about 37xc2x0 C. in 50 mM HEPES (pH 7.4), 0.2% BSA, 5 mM MgCl2, 200 KIU/ml Trasylol, 0.02 mg/ml bacitracin and 0.02 mg/ml phenylmethylsulphonylfluoride.
Bound from free [125I-Tyr11]SRIF-14 is separated by immediate filtration through GF/C glass fiber filter plate (Unifilter, Packard) presoaked with 0.1% polyethylenimine (P.E.I.), using Filtermate 196 (Packard) cell harvester. Filters are washed with 50 mM HEPES at about 0-4xc2x0 C. for about 4 sec. and assayed for radioactivity using Packard Top Count.
Specific binding is obtained by subtracting nonspecific binding (determined in the presence of 0.1 xcexcM SRIF-14) from total binding. Binding data are analyzed by computer-assisted nonlinear regression analysis (MDL) and inhibition constant (Ki) values are determined.
The determination of whether a compound of the instant invention is an agonist or an antagonist is determined by the following assay.
Functional assay: Inhibition of cAMP intracellular production:
CHO-K1 Cells expressing human somatostatin (SRIF-14) subtype receptors are seeded in 24-well tissue culture multidishes in RPMI 1640 media with 10% FCS and 0.4 mg/ml geneticin. The medium is changed the day before the experiment.
Cells at 105 cells/well are washed 2 times by 0.5 ml and fresh RPMI with 0.2% BSA supplemented with 0.5 mM (1) 3-isobutyl-1-methylxanthine (IBMX) and incubated for about 5 min at about 37xc2x0 C.
Cyclic AMP production is stimulated by the addition of 1 mM forskolin (FSK) for about 15-30 minutes at about 37xc2x0 C.
The agonist effect of a compound is measured by the simultaneous addition of FSK (1 xcexcM), SRIF-14 (10xe2x88x9212 M to 10xe2x88x926 M) and a test compound (10xe2x88x9210 M to 10xe2x88x925 M).
The antagonist effect of a compound is measured by the simultaneous addition of FSK (1 xcexcM), SRIF-14 (1 to 10 nM) and a test compound (10xe2x88x9210 M to 10xe2x88x925 M).
The reaction medium is removed and 200 ml 0.1 N HCl is added. cAMP is measured using radioimmunoassay method (Kit FlashPlate SMP001A, New England Nuclear).
The compounds of the present invention can be tested for activity in blocking Na channels. The compounds of the invention display binding to the veratridine-sensitive sodium channel. For the binding procedure see for example J. B. Brown, Journal of Neuroscience 6, 2064-2070 (1986), the contents of which are incorporated herein by reference. They block veratridine-induced glutamate release in rat hippocampal slice preparations. The experiment is performed according to a modification of M. J. Leach et al., in Epilepsia 27, 490-497 (1986) and Stroke 24, 1063-1067 (1993), using exogenous glutamate.
The compounds of the instant invention are synthesized according to the following procedures and examples. 
General procedure: An amine of formula (a) is treated with an aldehyde in a protic or aprotic solvent with or without an acid, preferrably chloroform with TFA, at about 20-80xc2x0 C. for about 5-72 hours. The resulting carboline (obtained as a mixture of diastereoisomers) can be isolated either by aqueous work-up followed by flash chromatography on silica gel, or by addition to the reaction mixture of a nucleophile supported on polymer (to trap the excess of aldehyde) such as aminomethylpolystyrene resin followed by filtration and then rapid purification of the resulting residue on a silica gel pad (using Alltech silica cartridge and Alltech manifold).